摘要
稀土(REE)和铌(Nb)是重要的战略性关键金属,位于南秦岭REE-Nb成矿带的庙垭碳酸岩-碱性杂岩体富含REE和Nb,碳酸岩以岩脉或岩株的形式侵入碱性正长岩中构成了一个全岩矿化的复式杂岩体。由于该类矿床常受到后期热液叠加改造影响,矿石矿物组成异常复杂,导致在稀土和铌矿物赋存状态、分布规律等方面未获得统一认识。本次研究以矿石的工艺特性为划分依据,将庙垭碳酸岩杂岩体划分成三大类工艺类型——混合型铌稀土矿石、氟碳铈型铌稀土矿石和独居石型铌稀土矿石,并针对不同工艺类型矿石研究了其地球化学特征、稀土和铌矿物的嵌布特征,查明了稀土和铌的赋存状态、分布规律的变化。其中铁白云石脉发育的混合型和氟碳铈型矿石稀土矿化最高,分别有91.83%和91.18%的REO赋存于稀土矿物中,而独居石型矿石中铌矿化最高,铌铁矿含量达0.65%,REO约有64.03%赋存于稀土矿物中,19.79%赋存于氟磷灰石中,且各类型矿石中综合利用回收的目标矿物铌铁矿、独居石嵌布粒度均微细,氟碳铈矿嵌布粒度呈氟碳铈型>混合型>独居石型的趋势。根据各自的工艺特性,混合型矿石适用稀土浮选-精矿强磁选工艺,氟碳铈型矿石适用稀土浮选工艺,而独居石型矿石则更适宜以浮选除杂-铌矿物浮选-强磁选工艺回收铌矿物。本次研究为庙垭铌稀土矿石的综合利用提供了科学依据,也为研究复杂杂岩体矿床中稀土和铌矿物赋存状态、分布规律以及成矿元素富集机制提供了新的视角。
Rare earth elements(REE)and Nb are important strategic critical metals.The Miaoya carbonatite-alkalic complex in the southern Qinling REE-Nb metallogenic belt is rich in REE and Nb.The carbonatite intrudes into alkalic syenite in the form of dikes or stocks,forming a complex rock mass with complete rock mineralization.Due to the frequent influence of post-magmatic hydrothermal alteration on this type of deposit,the mineral composition of the ores is exceptionally complex,leading to a lack of consensus on the occurrence and distribution patterns of rare earth and niobium minerals.This study divides the Miaoya carbonatite complex into three major process types based on the technological characteristics of the ores:mixed-type niobium-rare earth ores,bastnasite-type niobium-rare earth ores,and monazite-type niobium-rare earth ores.The geochemical characteristics and the distribution characteristics of rare earth and niobium minerals were studied for different process types of ores,and the changes in the occurrence and distribution patterns of rare earth and niobium were identified.Among them,the mixed type and bastnasite type ores with developed iron dolomite veins have the highest rare earth mineralization,with 91.83%and 91.18%of REO occurring in rare earth minerals,respectively.The monazite type ore has the highest niobium mineralization,with a columbite content of 0.65%,and about 64.03%of REO occurring in rare earth minerals,and 19.79%occurring in fluorapatite,the particle size of columbite and monazite in various types of ores is fine,and the particle size of bastnasite ore is characterized by bastnasite type>mixed type>monazite type.According to their respective process characteristics,mixed type ores are suitable for rare earth flotation concentrate strong magnetic separation process,bastnasite type ores are suitable for rare earth flotation process,while monazite type ores are more suitable for recovering niobium minerals through flotation impurity removal niobium mineral flotation strong magnetic separation process.This provides a scientific basis for the comprehensive utilization of the Miaoya niobium-rare earth ores and offers new insights into the occurrence and distribution patterns of rare earth and niobium minerals,as well as the enrichment mechanisms of ore-forming elements in complex rock mass deposits.
作者
李潇雨
熊文良
张丽军
朱志敏
Li Xiaoyu;Xiong Wenliang;Zhang Lijun;Zhu Zhimin(Institute of Multipurpose Utilization of Mineral Resources,Chinese Academy of Geology Sciences,Rare Earth Resources Application Technology Innovation Center of China Geological Survey,Chengdu 610041,China)
出处
《中国稀土学报》
北大核心
2025年第6期1366-1382,共17页
Journal of the Chinese Society of Rare Earths
基金
中国地质调查项目(DD20221679,DD20221809)
四川省科技计划项目(2023ZDZX0005,2022ZYD0126,2022JDR,2023NSFSC0272)资助。
关键词
铌-稀土
赋存状态
综合利用
庙垭碳酸岩-碱性岩杂岩体
niobium-rare earth
occurrence state
comprehensive utilization
Miaoya carbonatite-alkaline complex
